Went to a workshop recently and this was used as a opener. Have a group of five to 10 form a circle. Take a small beach ball and have the ball passed randomly or side to side. As the ball is accepted by someone they must repeat the last 3 words used and add a word that is somehow relative to the last word given by the passer.
Example: Blue/Ocean/Pacific/ = California Ocean/Pacific/California/ = San Francisco Pacific/California/San Francisco = Fog California/San Francisco/Fog = Snow San Francisco/Fog/Snow = Mountain
To speed it up the game, the group can also do a count down to eliminate participants. When a person repeats the passer's word, the group counts down 5,4,3,2,1 if the person can't come up with a word they are out.
If someone keeps track of the words, later for another exercise you can give the words to back to the group and have them use some of the words to make a short story.